The Skeksis are tall bipeds combining avian and reptilian characteristics. They wear elaborate but threadbare robes of lace, velvet, and brocade which apparently keep the skeksis' constantly decomposing bodies intact and make them look larger and more intimidating. Their heads are beaked like a vulture's but simultaneously sporting curved fangs. They have enlarged bellies and long reptilian tails, as well as curved quills on their backs. They have two pairs of arms but only one functional the other reduced... despite their frail appearance they are powerful creatures.

It should be no great revelation that this post will serve as the most subjective and probably therefore most controversial in this series. Experience in electing novel soft tissue structures in T. rex and Smilodon has taught me that much...

It should also come as no surprise to readers that I am no great fan of dapper dromaeosaurids - a look that has come into vogue in recent years.

Dapper /'dapper/ adjective (typically of a man) neat and trim of dress, appearance, or bearing.

Deinonycus antirrhopus credit John Conway CC3.0

How did this look evolve? It is not too hard to trace a lineage of inspiration from Gregory S. Paul who retooled dromaeosaurids as feathered and decidedly bird like to John Conway who took a lot from Paul's look and made these animals even more birdy to Emily Willoughby one of the leading contemporary dromaeosaurid paleoartists whom has greatly inspired the dominant ground hawk look.

Acheroraptor credit Emily WilloughbyCC3.0

A commonality in all three of these artist's look is the clean cut juncture on the facial region separating feathered from non-feathered parts. This clean cut visage, almost always combined with an attractive feathery countenance lifted from a modern bird of prey (red tailed hawks and peregrine falcons are common suspects). A look that has been consistently aped and imbued itself into the dominate appearance of these animals in paleoart.

Peregrine Falcon credit Magnus Manske CC2.0

Gregory S. Paul hypothesized a "proto-beak" around the mouth of his dromaeosaurids and other maniraptorans. Basically an area free of integument and slightly cornified. See here and here. Essentially it was an inference made on the perceived - and correct - relatedness to modern birds.

The problem is that we do not have any evidence of a proto-beak in dromaeosaurids or any predatory maniraptorans at all for that matter. Nothing, nada, nunca. Nor do we have any evidence of the type of clean cut juncture depicted by Conway & Willoughby which has influenced current depictions.
Mathew Martyniuk discussed this seldom mentioned meme in an excellent post The First Feathered Dinosaurs (In Art):

"Paul essentially invented the latter meme (half feathered faces) in an attempt to make his theropods look more bird like (by suggesting a sort of beak), and while this was his own speculation, many later artists ran with it, including in early drawings of Sinosauropteryx."

While Conway's and Willoughby's renderings do not necessarily imply the sort of "proto-beak" structure that Paul hypothesized both of these artists kept the clean cut dapper "featherline" which Paul used demarcating a solid break from the feathered region of the head and the bitey jaw region. This trope has imbued itself into countless depictions of dromaeosaurids since, to the point that it is in many ways the de-facto way to depict the heads of these animals in many people's minds. Just remember - if you chose to depict dromaesaurs this way you are merely inheriting a trope that has no basis in evidence of either a proto-beak or a defined juncture between feathers and non-feathery covering on the heads of these animals. Not saying it is impossible that some dromies did not have such a juncture just that it is based on a hypothesis of a proto-beak which has not been borne out evidence wise but remains with us as an attractive speculation.

Indeed feathers covering the entirety of the head (except maybe the nostrils left open ala mammal noses) is what might be the more parsimonious interpretation as suggested by Sinornithosaurus and Zhenyuanlong. With no evidence of a proto-beak in these animals there is no reason to assume feathers did not go all the way to the oral region.

Sinornithosaurus 'Dave' credit DinoGuy2 CC1.0

This actually opens the doors for a lot more play as goes the facial appearance of these animals. As it should be, because we should not expect a lineage of animals that evolved and lived in diverse conditions for over 100 million years to all look a like. Everywhere from fully feathered to yes, naked skin, or in between.

You know I loves me some vulturine inspired dromies. I really like how the tail display, arm-wings, contrasting white/dark colors, and jaw are all used together in threat display. As I argued in my last post there is at least as much - if not more - to glean from vultures as analogues to many dromaeosaurids as there is from raptorial accipterids. Also note that the feathers are plumaceous like in an ostrich not the stiff venaceous feathers we have often seen in paleoart.

Tsaagan. credit Matt Martyniuk CC2.5

I am a little surprised at the blowback I receive in electing naked headed, gnarly faced, caruncle ridden dromaeosaurs as a likely look for many of these animals. But why not? I am fully willing to concede my bias for ugly, uncouth, goblin looking critters duh.... I wear my inspirations on my sleeves baked in bong hit residue, blotter acid, splatter films, and swedish death metal. That does not mean I am in fact wholly wrong. More to the point, I would suggest others are less open than I am in conceding their own biases. Do I suspect that some people really have a penchant for the attractive, elegant, and refined look of dromaeosaurids that has come into vogue? Essentially a grounded peregrine falcon or red-tailed hawk? That such elegant, attractive, and appealing visages have a conscious or subconscious appeal to many of the artists and fans who endorse such a look even going so far as to assert "this is how they looked, period". Wrapped up in a nice little bow because of the RPR hypothesis - which as I have mentioned again and again Fowler stated specifically dromaeosaurids were not as strong graspers as modern accipterids - fueling the typological thinking to dress up a Deinonychus as a grounded red-tailed hawk? And that people who have such a definite and emotional attachment to such a look would be dismissive and threatened by my interpretation asserting a more vulturine influence? Nah, that never could happen snark, snark...

Just to keep in mind I am getting my inspiration from birds too, and not all birds are concerned with looking regal and elegant...

For every grey-crowned crane I can raise you a helmeted hornbill;

helmeted hornbill. Rhinoplax vigil Doug Janson CC3.0

For every great blue heron I give you a marabou stork;

Marabou Stork (Leptoptilos crumeniferus) credit Rusty Clark CC2.0

(end of rant)....

Truth is we do not have a lot to go on in terms of facial appearance of the medium to larger dromaeosaurids that lived in open and/or hot & arid environments. Painting with broad strokes I would lean more towards fully feathered heads for smaller dromies/small game specialists especially in closed temperate environments - essentially Liaoning. But for dromies that were out in the open, fighting and competing over carcasses, going toe to toe with carchs, abelisaurids, and tyrant lizards, in hot and/or arid environs a naked head with fleshy adornments is a defensible position. Many of the more famous dromies such as Velociraptor, Deinonychus, Utahraptor, and Dakotaraptor fall in this category.

Large exposed patches of skin on the head and neck can serve a thermoregulatory function and also social signaling. Blood can be flushed into caruncles, necks flaps, and other skin adornments in colorful threat dominance displays as occurs in condors.

Andean Condor credit Kevin Law CC2.0

Whenever I talk about fleshy skin adornments on theropods - including large lips - there is a consistent critique that people chime in with: "but these areas would be targets for biting by conspecifics and get snipped right off!?!"
Let me offer some rebuttals (takes a deep breath):

1) Losing a chunk or flap of skin is still preferable to losing an eye or getting a bite on the neck or vertebral column which could have fatal results. That being said skin can be amazingly strong, elastic, and (best of all) it grows back. Hyenas, bears, badgers and yes vultures are often noted for the strong and elastic properties of their skin that allow them to suffer abuse that would seriously lacerate lesser skinned animals. Theropods - and especially combative dromies - had all the reason to not only have such thick and elastic skin but abundant skin derived display structures. Just look at the skull of a male andean condor, there is no tell tale osteological signifier that it looked like the mug above.

2) Which brings me to my next point. We already have compelling and irrefutable osteological evidence of display structures on other theropod skulls (Dilophosaurus, Guanlong, Monolophosaurus etc. etc.). That these animals would grow such features in a highly visible and vulnerable part of the body complete with thin struts of bone - and they were not snipped right off - is all the more compelling reason to suspect a more widespread and outlandish panoply of soft tissue structures throughout theropoda (and many dinosaurs in general) that would not preserve. Especially among those theropods that were regularly coming together socially at large carcasses in feeding events/social gatherings. Dromies certainly count in that regard. In fact we should predict such structures.

3) Which leads right into my next point - prediction met (sort of) !! By now many readers have doubtless heard of the (as yet undescribed) evidence of a large distensible gular neck structure on a Tarbosaurus bataar. If this story pans out we do have evidence of a fleshy display structure on a lineage of the most bitey theropods of all time in the most vulnerable part of the body. So putting a highly visible, likely brightly colored display structure on the neck of the most powerfully biting terrestrial tetrapods of all time still panned out in the Darwinian struggle.

4) Such critics have probably never really been in a fight or done poorly in one... really don't take it as an insult because fighting and violence in humans is not really a good trait to endorse. But looking at what professional fighters and strikers do and the tactics that they use can be useful. One common tactic used in boxing is to intentionally offer up a shot that puts your opponent in a vulnerable position by feinting a move and then counter-striking. Let's go through what happens when a "vulnerable" fleshy skin adornment (or large lips) are bitten by another theropod.

I In a dispute one theropod bites the skin flap on the chin of another theropod. Due to the strength and elasticity of this skin it is not simply cleaved right off but instead substantial yanking and pulling would be needed to remove such structures.

II As the theropod that did the biting - let's call it theropod A - pulls and yanks that piece of skin off the bitten theropod - theropod B - and finally cuts clean the skin structure the momentum of the pull off will move theropod A downward and lateral from theropod B.

III At this point it is theropod B - the bitten theropod - that has tactical advantage. Theropod A in the course of yanking off a chunk of skin has put its head and neck inferior to theropod B.

IV Theropod B can now attack theropod A and get a potentially fatal or devastating bite to the back of the neck or head of theropod A. More importantly theropod A can not retaliate when bitten from this position at the back of the neck/skull.

V Theropod B has lost a piece of skin that can potentially grow back. Theropod A has in its miscalculations put itself in a vulnerable position and although it successfully inflicted non-fatal damage by removing a chunk of skin it may potentially lose its life because in doing so it left the back of its head and neck open.

"Bite my lips I dare ya'" credit Tiia Monto CC4.0

Watch brown bears fight. Their big, jangly, fleshy lips are mere inches from one another yet they are not targeted. Because bears are better tactical fighters than most people. Bears know better than to commit to a non-fatal attack that might leave them open in the end.

One final word on theropod facial biting/skirmishes. I suspect the vast majority of bites were not the bone scraping/puncturing potentially fatal traces we see in the fossil record. The overwhelming majority of interactions that went beyond theatrical displays and gesticulations were probably the fast little nips and non-committal bites we see among canids and social feeding birds. Many of these bites would not even break the skin.

I will delve more into display structures in theropods in the future because I think that they are a fascinating topic for exploration. Instead of asking how much or how little these feature were found in theropods - as you can tell I suspect that they were quite widespread - I think we should be asking why are mammalian predators (and I guess you can extend this question to predatory monitor lizards) so impoverished when it comes to display features?A Long History Of Dromaeosaurid Evolution Lots of Room For Variation

If we accept a middle Jurassic origin for dromies of about 167 mya that gives us more than 100 million years of dromaeosaurid tenure of small and medium sized carnivorous theropod. That is longer than felids or canids have been around. More importantly that is longer than ratites have been around.

I really want to drive home the ratite comparison because dromaeosaurids are increasingly likely secondarily flightless - probably evolving from something like Microraptor that could glide if not fly in a limited capacity. So if we look at ratites it becomes apparent that they have done all sorts of weird things with their feathers once they became permanently grounded. Especially so with their flight feathers. Ostriches no longer have the stiffened vennaceous wing feathers of flighted birds but more open plumaceous ones. Cassowaries have quilled wings. These options are real possibilities for dromaeosaurids but should be analyzed and imbued within a likely evolutionary/ecological framework.

Cassowary. credit Gambier Bolton

In my last post I depicted a Dakotaraptor that veered very far away from other restorations. What I put in that rendering is quilled tail feathers. No need to incur drag when you are that cursorially adaptated. No longer a flighted animal or even one that could glide at that size I posited quills on the tail as a weaponized exaptation useful for whipping around at theropod dinner parties and also for rattling in threat display. Visual, auditory, and physical threat and intimidation displays should all be on the table when considering dromies. They were likely some of the most gruesomely theatrical animals when gathered in group feeding bouts in the history of terrestrial carnivores.

I also gave Dakotaraptor a striking white feather patch on the front of its chest for bold display and intimidation. Such bold white patches - when contrasted against darker integument - are common in birds of prey and also some mammals such as various species of Asiatic bear.

Ursus thibetanus. credit Guerin Nicolas. CC3.0

I took this notion of feather disuse and even extreme reduction further in a rendering showcasing a Dromaeosaurus feeding scrum on a non-descript chasmosaurine ceratopsid. An azhdarchid and a troodon are looking on waiting for scraps.

feeding scrum by Duane Nash click on image for bigger shot

As you can see I really took the hyena analogy to the extreme even to the spotted scruffy coat. I reduced the wing feathering and eschewed tail feathers completely as this ground based, running, scavenging dromie had little need for them.

I also gave Dromaeosaurus a thick neck mane of coarse feathers for protection during skirmishes.

100 million years of terrestrial evolution from likely flighted ancestors allowed for substantial variation in appearance and function of dromaeosaurids; modern flightless birds show that flight feathers can become plumaceous or quilled; aggressively combative, usurping, and scavenging dromaeosaurids especially in hot and/or arid environs likely featured large areas of the head, neck, and chest bare or with feather reductions; such areas could have sported extreme skin adaptations that offered thermoregulatory, protective, social, and intimidatory benefits; for these dromaeosaurids new world vultures (cathartidae) and old world vultures (accipteridae) might offer more useful analogue behaviorally and physically than raptorial birds of prey (accipteridae); feathers could additionally have been arranged in coarse manes or thick tufts around the neck for protection as well as bold white/dark contrasting areas for intimidation.
One final note and this has to do with anthropomorphism - the ascription of human values, conceits, and emotions onto animals. One charge I have seen leveled at me is that I, to paraphrase, "depict many of my animals intentionally weird, ugly, or unattractive". To which I reply "duh, goal achieved".

I have always been transparent with my inspirations culturally on this blog - informed as I am by ugly music and ugly movies. I think it important that researchers be transparent with their inspirations, not just their scientific ones, to most reveal potential biases. We are all primarily cultural critters and it would be naive to think even the strictest and staunchest scientists are not first and foremost cultural creatures.

So when one looks at vultures gobbling and skirmishing over a carcass or the scruffy, uncouth appearance of hyenas and their cackles and the words "horrific", "disturbing", "ugly", and "revolting" are bandied about is this a cultural reaction or a more intrinsic, base natural one? Let us flip our way of thinking about combative scavengers... do we think about them with these conceits in our mind because of culture, or, because we ourselves are animals and most animals want to move away from the sight of such animals feeding? That is the that the shock, the visual awe, the intimidation we feel at the sight of these feeding events is the same gut level emotional response other animals feel: "I don't want to get near this cancerous looking, tumor faced, loud, shrill, dominating, repellent, and combative animal not because of some cultural tradition but because I too am an animal and I react on a visceral level to this display?"

Coming up a new hypothesis on dromaoesaurid biting technique because it really is all about the teeth...

"A Long habit of not thinking a thing wrong, gives it a superficial appearance of being right, and raises at first a formidable outcry in defense of custom". Thomas Paine

43 comments:

Just so you know, Zhenyuanlong is flightless and it has non quilly tail fans. While not a dromaeosaur, caudipterids also do not fly and have tail fans. I'm sure that the majority of dromaeosaurs still had tail fans similar to Zhenyuanlong.

Wow, you actually make a compelling case towards quilled Dromaeosaurs. I'd never think that I'd say this, but it's time to draw some quilled Raptors! But keep in mind that it's likely that the juveniles of many species were still somehow volant. Not nesecarily by flapping, but more along the lines of gliding from a high point, or simply running along the ground while spreading their wings to manouver better. Is it possible to have quills and "ordinary" vained feathers at the same time? Imagine the wings of the Dromaeosaur with pnnaceous feathers, but also on the arm are a few cassowary like quill feathers between every pennacious feather or two. Would that be possible? It would be great for gliding/manouverablility and attraction, but still useful in nudging the hell out of a competitor.

@Kiera Sonniksen Zhenyuanlong is a basal member from a temperate to sometimes even cold climate and is also a small game hunter. It doesn't fit the general "criteria" of having quills/any form of groundless bird feathers since it lives in a cold area and doesn't really need wattles, quills, etc. seeing as how it's not gonna be a common site at a carcass. Plus it's still basal so it's not that far away from the general ancestral line of floofy, more "traditional" Dromaeosaurs. And Caudipterids aren't a good analogue since although they are flightless, the are essentially the Mesozoic equivelent to grouse, pheasants, Peahens, etc. since they are flamboyant flightless herbiores/omnivores. Why would they need wattles and quills if it's just an oversized peacock? And even if it needed quills/wattles/etc., it's still a very basal member so it's not gonna have a lot of derived features.

Thanks for coming by and commenting Kiera Sonniksen. Your point about Zhenyuanlong and caudipeterids is taken.

"I'm sure that the majority of dromaeosaurs still had tail fans similar to Zhenyuanlong."

Not sure what your point is. Are you saying that I should not play around with an integumentary trait that might indeed show much variability and diversity over the course of 100 million years? Just so you know, that is a long time for an integumentary trait such as feather morphology to be in stasis. For all dromaeosaurids to be that particularly conservative with an integumentary structure over that amount of time I just can't buy into that line of thinking.

@khalil quills and pennaceous feathers together on the same arm there likely are some evo-devo constraints to think about that might preclude that. It is possible that the tips of certain pennaceous feathers were stiffened and robust - weaponized to an extent for wing pummeling and rough use all around.

@khalil also I would not assert that quills and wattles are associated strictly with hypercarnivory/scavenging and Kiera brings some valid counterpoints. After all many pheasants, quail "gallifornes" have loads of fleshy facial structures and don't battle over carcasses. It is not a 1:1 type relationship. Also cassowaries are frugivores and I am not sure what they use their quills for!?

My main point is that there is still lots of room for play in terms of how these animals appeared and what they gained and lost over 100 million years of evolution. Future discoveries may hem the debate in to an extent but at this point I would not be too dogmatic in reconstructions that are within the bounds of reasonable and adaptationist speculation.

Ok, I am just going to say it right out there about the appearence of dromaeosaurs.

One of the things I find with the bald head hypothesis is that all the birds that do have these are either herbivores or obligate scavengers. Raptors were neither. They were facultative scavengers. If we look at modern birds that are hunters and facultative scavengers, they all have feather faces. They include ravens, crows, caracaras, hawks, and even eagles.

@khalil Living in a temperate cold environment doesn't really make a difference. Are you saying that dromaeosaurs living in warmer envrionments wouldn't need tail fans, because I find that a bit extreme. It should be noted that Hell Creek (where Dakotaraptor is from) is not as warm as many people think it is, the dry season being as low as 4°, and the wet season being as warm as 14°. While not Yixian cold, that's still pretty cold.

@duanenash My argument is that there is no evidence for quilly tailed dromaeosaurs. I'm not saying it isn't inpossible, after all they did exist for a while and I'm sure they had some variation in tail fans, but I wouldn't go as far as saying most of the terrestrial species had quilly tail fans. Until we find a fossil impression of a quilly tailed dromaeosaur, I would just say this is artistic license, but not anything grounded in deep science.

@khalil Basal member, yes that is a valid point, but I'm inclined to say there are more uses to a fully plumaged tail fan than a quilly one. For instance, while dromaeosaur tails are pretty stiff, as with scene in that Velociraptor specimen they can be quite bendy, so they can provide more warmth. Also, I highly doubt temperature is going to play a big role in tail fan shape and size. Peacocks have enormous tail fans and live in a pretty warm envrionment. Also, the discovery site of Dakotaraptor (Hell Creek) is not as warm as many people think it is, about 4-14° annually.

@duanenash I'm just skeptical that most ground based dromaeosaurs had quilly tails. They did exist for a long time and so there probably was some variation in tail fan shape and size, but things happen for a reason. A tail as a combat weapon... I'm inclined to disagree with that, but hey, it's artistic license right? Nothing wrong with that. I would like to see a fossil impression of a quilly tailed dromaeosaur, maybe soemthing like the tail feathers in sage grouses?

@D-man "All the birds that have these (bald heads) are obligate scavengers" Nope many vultures do kill. More to the point they bite and fight a lot. As do marabou storks and ground hornbills. And many feathered birds of prey primarily scavenge such as bald eagles and caracaras.

Did I suggest that cassowaries have quills all over their bodies? Go back and read the text never said or implied that for cassowaries or dromies for that matter. Just suggesting that over the course of 100 million years of evolution some - but not all or even most - dromaeosaurids could have had flight/tail feathers that reverted back to quills. Sheesh I am amazed people are struggling so hard with that idea, it is not even that outrageous. Nor am I dogmatically insisting that you should depict dromies with quills or that you are wrong if you don't. Quills are a possibility.

I do have to point out the irony in this situation and how my "artistic license" or better yet "fringe" interpretation is met with resistance but the clean cut, dapper look that Gregory S. Paul started with his - never proven - hypothesis of a protobeak and which Conway and Willoughby piggy-backed on with their clean cut raptors always gets a pass. Let me remind you that that interpretation is as much an artistic license as mine as. Yet any artist that apes that particular trope - again no proof of a featherless boundary layer on the head or a protobeak at all in dromaeosaurids - they are met with unquestioned praise and congrats. Again, for a hypothesis that was never proven.

So if anyone is going to cast shade my way for my interpretation and take the time to write a comment on why my interpretation is subjectively "improbable" or "unlikely" at least be even handed and concede that the majority, unquestioned visage - the dapper ground hawk model - is also a trope based on an unproven hypothesis of a protobeak. I suggest you do the same for all the other interpretations aping the featherless protobeak trope of Paul-Conway-Willoughby. Cast a critical eye towards all interpretive and speculative restorations - not just the ones you find displeasing.

Fact is I can no more prove that dromies did not look like ground hawks than you or anyone else can prove that they did not look like grotesque ground vultures. So why not have depictions of both and just be okay with the ambiguity?

Hi, I've been lurking this blog for some time and I just want to say that I find your writings quite enjoyable and thought-provoking, it's been years since paleontology has last felt quite so new, alien, and fascinating to me as when I first started reading this blog.

While I must confess that I still have an aesthetic preference for the "ground hawk" model (this is, of course, just my personal preference and I won't pretend it has any influence on what was reality millions of years ago), yours is indeed a valid alternative that seems just as plausible to me. Your quill hypothesis is certainly intriguing, I'd be interested to see if any solid evidence for this pops up in the future.

Anyway, keep up the good work! The questioning of accepted paradigms is what helps to drive science forward.

Comments like yours really really inspire me and make this all worthwhile. I would like to say that i don't care what others think or that I just do this just for myself - both of which are not totally true...

And there is nothing wrong with having an aesthetic preference - in fact it should always be assumed to be part of any paleoartistic depiction. I blatantly telegraph my aesthetic preference for the bizarre, macabre, and disturbing - does that mean that there were not in fact dinosaurs that actually fit the bill, of course not!! Likewise there were definitely very beautiful and attractive dinosaurs.

Anyways glad you "get it" and hope to hear more comments from you in the future DinoPedia!!

Interestingly, I think one could draw parallels between video game culture and the reactions to your paleoart. Censorship was a real threat to video games not too long ago, and so certain sectors of video game fandom are still so hyper-attuned to that threat that they make this huge boogeyman out of people they call "social justice warriors". This visceral reaction against people like Anita Sarkeesian is born out of a communal fear that the "outsiders" are coming to take video games away.

Similarly, fans of scientifically accurate dinosaurs have been fighting an uphill battle against the "awesomebros" for decades now, outsiders who also seem to have the power to keep culturally dominant depictions of dinosaurs stuck firmly in "The Age of Reptiles". The phrase "feathers look stupid" has been assaulting true paleofans from all sides for ages, so most are hyper-sensitive to anything they fear might play into that stereotype. Granted, gnarly vulture-mimics don't look stupid, but I think many fear the ugliness might still turn people away.

@Keira Sonniksen I never said that warm weather "Raptors" wouldn't have a fan tail. I never said anything about warm weather species not having tail fans. Tail fans would still be incredibly common, especially for small sized forms. I said that Zhenyuanlong isn't a great example for the norm of "Raptor" integument since Dromaeousauridae is such a varied, wide spread group over 100+ million years, yet you only use the very specialized basal forms as an example. I clearly said that since it's basal, is essentially a fox like small game hunter and is found in a cold environment. So having wattles isn't as likely since not only is it in a cold environment where heat loss via a bald head isn't nesecary, but seeing as how it's essentially a fox in terms of ecology, it doesn't really need wattles to fight over a carcass. It could still have wattles for intraspecific combat anyway, but it's not needed, it would just be slightly possible. And yet again, it's very basal, so how do you think that such a basal, specialized form is somehow the norm for an incredibly varied and long lasting group? And how is Hell Creek so cold when it has an incredibly similiar flora and even fauna (i.e. crocs, fish, etc.) to modern Florida? It clearly supports a wide array of tropical to subtropical organisms. And your arguement against wattles because of eagles and hawks isn't that great either, seeing as how not only do most species specialize more in live prey (with some notable exceptions) where they don't have to squabble over a large carcass, but many don't bite or specifically go for the neck/head. Eagles often times kick and grab eachother with their talons. It can also be seen when scavenging that they often jsut use their sheer size and strength to bully other scavengers. They do so by jumping at a competitor or simply by just squaring them up. But this isn't really affective against vultures since they essentially "fight dirty" by biting the head and neck. This isn't as big of a problem if you're a vulture being attacked by another vuluture though since you have wattles to protect your vital parts, but if you're a "majestic and elegant" eagle with a full haed of feathers, that's an issue.

@Andrew Raymond Stuck Interesting, I remember something about the big kerflunckle in gamer culture over perceptions of rape culture, misogyny, and the like by a vocal cadre of feminist gamers. I dunno how you can deny those allegations after playing or watching any of the Grand Theft Auto games they are pretty ugly towards everyone, but especially females. If I recall a major part of the criticism is that females make up a big part of gamer culture so why not have games that empower and respect females as leaders and heroines? Seems pretty cut and dry to me. And then there is the backlash to female leads in the ghostbusters revamp... sheesh get over it dudes females have been right here all the along kicking ass in their own ways. Instead "social justice warrior" is now thrown around like a pejorative - how did being a warrior become a bad thing? I would love to be insulted with the word warrior. Seems to me many females both in the U.S. lead more heroic struggles in their day to day existence than the average male who just wants to wave his (penis, gun, ego, religion) over the whole world like a shit throwing ape.

Keep in mind I am 100% against censorship. But in my opinion censorship is mandated by the government. If free individuals make a product that others don't like for reason x, y, and z then those that don't like it can call it dumb for those reasons in a free society. That is not censorship. That is you having the freedom to say a dumb thing and me having the freedom to call it dumb.

Anyways breaking some of my commenting rules as this is a little off topic... but not really because future posts will play with dinosaur appearance and gender again in the future in weird and disturbing ways so stay tuned.

@khalil and @Kiera OK you have both said your pieces let us reign it in a bit now. We have reached an internet impasse level 5.

It is not a 1:1 to one relationship between face biting and fleshy head structures. Just because animal x does a lot of face biting and does not have fleshy, thick facial growths does not negate animal Y which does a lot of face biting and has loads of facial structures from having these growths.

Social display, bluff, intimidation, thermoregulatory functions all play into fleshy and skin derived facial structures as well, not just biting stuff, a precept people have seemingly latched onto and won't let go of in their critiques.

I think you, Bk Jeong, and others are being overly dogmatic and to put it quite frankly very subjective with terms like " I doubt it" or " I don' think so" being used to assert >how wrong< I and others are on this topic . This type of thought policing in paleoart really has little room for appeal in paloeart. In fact i would go a step further it really has no place in paleoart at all. Yes, such dribble adds nothing. And it is almost always made by people who don't create much themselves. It creates barriers where quite frankly we don't need barriers. It creates walls of resistance where they don't need to be.

All paleoart really is, is hypotheses to one degree or another. To potentially be proven or dis-proven down the road.

There is currently nothing you or anyone else can come up with to refute the hypothesis of fleshy skin derived structures on the head and neck of dromaeosaurids and other maniraptorans/theropods to various degrees. Giant petrels being Antarctic/ sub antarctic birds with fully feathered heads never would have had the open areas of skin for such features to evolve. Which is consistent with my belief that small and/or cool adapted dromaeosaurids likewise had fully feathered heads. I doubt the protobeak look which- if you want to target an unquestioned dromie meme - that is the one you should concentrate on - not just the fringe work of myself which has comparatively little effect on paleoart tropes.

But that protobeak look is ubiquitous across paleoart. Much more than fleshy-headed/wattled dromies.

Do you really want a world where every derived medium to large dromaeosaurid looks like a 4th generation Emily Willoughby knock offs? Yawn.

I am on the whole quite a bit annoyed and it should show in my response. Why do I always have to repeat myself? Why do people comment without really reading and digesting the whole article? Why are some paleo-fans so insufferable?

So I consider the matter closed and will likely not comment on this matter further in this post. Don't expect me to post further comments on this argument Bk Jeong. In fact if you nag me on it on with further comments on this or other forums - as you have done in the past - consider yourself on the permanent banned list. I am not obligated to spend time I could otherwise spend being productive volly-balling back and forth with you in pointless internet flame wars.

You know, now that I think about, almost all old world world vultures (except for the Lappet faced, Egyptian, and Red headed) have pretty dapper heads.https://www.stlzoo.org/files/9613/0798/4097/cinereous_vulture1.jpghttps://upload.wikimedia.org/wikipedia/commons/5/51/Griffon_vulture_headshot.jpghttps://en.wikipedia.org/wiki/Himalayan_vulture#/media/File:Himalayan_griffon_(Gyps_Himalayensis)_in_Spiti.JPGhttps://en.wikipedia.org/wiki/Hooded_vulture#/media/File:Necrosyrtes_monachus_-Sabi_Sand_Reserve,_Mpumalanga_province,_South_Africa-8.jpghttps://en.wikipedia.org/wiki/White-headed_vulture#/media/File:Trigonoceps_occipitalis_-Las_Aguilas_Jungle_Park,_Tenerife,_Spain-8a_(4).jpg

Speaking of carcass rendering, wattled Dromies, what was Achillobatar doing? It fits in the size range of terrestrial scavenger, yet it's legs (just like Utahraptor) are incredibly short and stumpy, while also roubst. Was it still able to trek for miles on end like it's more cursorial counter parts, or would it waste too much energry trying to get there? And if it's not scavenging, then what was it doing?

Hi Duane, first of all, I'd like to say that you've enormously reinvigorated my interest in paleontology. Your posts have seriously captured my imagination, and I hope there are many more to come.

I was wondering if you had any plans for the animals you'll cover after the dromaeosaurid series is finished. I was curious what you thought of iguanodonts and hadrosaurids, since they're both two very successful groups of herbivores that don't seem to get much respect. I mean, they're usually depicted simply as lunch for whatever giant theropod lives with them. There is clearly more to them in terms of defense or, more broadly, predator evasion strategies than I've seen posited.

Back to dromaeosaurids, what niche do you think mid sized animals like Deinonychus occupied in their environments?

@ D-man I think you misconstrue what I mean when talk of the dapper look. What i most emphasis in that description of "dapper" dromaeosaurids is the abrupt clean cut transition between feathered and non feathered parts of the head. Gregory S. Paul hypothesized a protobeak for establishing that look, a hypothesis that has not born out. Other artists merely inherited that look and kept it alive for no other reason than tradition. It could be possible that the feathers covered the whole head all the way down to the teeth. Also possible that feathers sparsely covered the head. Also possible that the dapper look is common. It is also possible that fleshy outgrowths occurred in some species. But I explained all this in the post... why do people have such trouble understanding this?

Long story short it is possible and probable that dromaeosaurids displayed all the variety of facial/integumentary arrangements we see across birds of prey and many other birds today.

What I have trouble with is that I am dragged across the coals for preferring a subjectively ugly look, giving reasons why I think it was probable in some genera, and deviating from the norm. While other artists keep drawing samey ground hawks with caudipterid tail plumes and getting a pass. Go bug them there are plenty making the error of caudipterid tail plumes on deviantart. But I already said all this.

@negosolar Thanks. Lots more posts in the future so you are in for some neat stuff but nothing specific on big ornithopods though I do like them a lot and everything you said is true of them.

@khalil I can't find a lot on achillobatar. I am not sure that shortish legs implied an inability to travel long distances. Bears are good long range foragers/scavengers after all.

Good point on Achillobatar. I think it was essentially like the Lappet faced vuluture in terms of carcass presence now that you mention how bears are great scavengers regardless of how stumpy their legs are (compared to cursorial carnivores). It could still get to the carcass, but seeing as how it was incredibly robust, powerful and had a robust killing claw, it could dominate a carcass. And I was actually wrong about the legs. They aren't short afterall, although the body itself (especially around the hip) is very massive and robust:http://vignette1.wikia.nocookie.net/theropods/images/8/86/AchillobatorSkeleton.jpg/revision/latest?cb=20131023184852I wonder what it was doing if it needed such a massive hip area.

I'm truly diggin the artwork here Duane. Your pieces feel so immersive and realistic this combined with your sketchy style really work well together. I especially like the plants in the ceratopsian pic with all the ferns and vines etc. While I agree I love the refined look of many creatures as Mark Wilton makes emphasizing that these are animals not horror movie creatures, but I love your Macomb and gross appearances with the all the grittiness. I wonder how long did it take you to draw each of these pieces individually.

Also I hate to say t but my initial knee jerk reaction when you mentioned quills was, ohh that can't be very common etc. obviously that is not what you were saying I feel sorry for my lack of critical thinking. I think it was because of our recent series on smilodon and its complete reimagining of it. I then associated that with your raptors when this articles message is completely different, it merely suggest a diversity and not one solid image of depictions.

Last point wouldn't the super large azdrahcids like quetzalcoatlus and arambourgiania dominant/equal rivals all of the dromeasaur except for giants like Utah raptor and large tryants at kills.

Sometimes I think I rub people the wrong way and somehow give the impression that I am saying " this must be the way to do it all other ways are invalid!!" when in reality all I am suggesting is that in 100 million years of evolution, covering variable eco-morphotypes, in various environments from hot to cold we should expect to see various changes in integument and varieties of appearance. Possible at least as much as we see in birds of prey - falcons, hawks, eagles, and yes vultures too - maybe even more!!

Is that really that outrageous? I mean come on... that I would dare question the ubiquity of the ground hawk look or even suggest that there are alternatives that are not even necessarily mutually exclusive (i.e. there may very well have been both very hawk looking and vulture looking dromies one does not negate the other).

On the artwork the dromaeosaur feeding scrum took a bit of a time, don't recall but a lot of time on the vegetation that is for sure. Overall though I try to take a very punk rock, no frills, don't overwork things approach and go for a vibe, reaction, or gut level response not necessarily hyper realistic but gets the point across.

D-man What does that even mean? No one has seen any of the animals alive!?? That is the point of all this.

also dromies vs azhdarchids? Of course they met up, seems to me that it was the pterosaur ending up in the belly of the dromies more often than not (scavenged or otherwise)... sure the big giant ones could dominate just by size but more modest and small ones probably hung around the periphery of carcasses just like marabou storks do today. Take away any kind of size advantage and I am going with the dromie every time.

Not really sold on the hypercarnivorous attributes some like to ascribe azhdarchids as if they were actively pushing theropods out of their niches. I have heard chatter about that Romanian giant, Hatzegopteryx - being more of a predator of medium to large stuff BUT where are all the pics? Plus they were pretty cumbersome opening up thick skinned dinosaurs with a bill that amounts to a giant pair of foreceps. May have been good at moving into a kill after other animals have opened it up, using its size to gain advantage and get at soft entrails etc etc.

That being said I would love to be proven wrong and the giant Romanian showing some neat adaptations of the bill for hypercarnivory - just have not seen it yet. Supposedly there is a skull, the wiki article goes pretty in depth but how come no pics yet? Frustrating.

And that neck?! You would think there would be some sort of enlargement of muscle attachment in the cervicals if it was always jabbing and thrusting with it but it was like a tube without much in the way of muscle attachment - just weird all around.

To tell you the truth I would be more interested in giant tapejarids and dsungaripterids muscling in on dromies...

Dromies vs azhdarchids could be very similar to the ongoing competition between vultures and canids (hyeanas too) for scavenging rights. Also very possible that dromies watched the skies for movement of pterosaurs for carcass finding.

I don't have time to read all the comments here in detail but just to chime in...

1. Excellent post and something a lot of people involved in the internet paleoart scene need to read. I can already see the memes of the next decade solidifying over the past few years and it will be good to bust them early!2. But sometimes it's fun to draw memes. I put a red rhamphorhynchus on the cover of my last book ;)3. But we do need artists who are willing to challenge memes and suggest new ways things could look. That's why All Yesterdays exists. I think many of the people commenting here would do well to read that book (again, if necessary). And look up hat "straw man" means. I can't grasp how somebody could possibly have read your post and come away thinking you said most dromeosaurs were covered in quills.4. I want to point out that while people are using Caudipteryx as an example of a conservative, basal form, it has a lot of bizarro highly derived traits like a tail fan restricted to the tip of the skeletal tail and possibly broadly forked; tiny, oval shaped wings restricted mainly to the manus without any secondaries which are there and BIG in many other feathered dino specimens, including Similicaudipteryx; and out of the four or five good specimens we have, zero show any trace of feathers on the head and neck, strongly implying those areas were covered in skin or very sparsely feathered as in many ratites. So Caudipteryx kind of proves your point about diversity, since its close relatives are much more "normal" (=basal-looking?) in a lot of ways.

I'm gonna end with an anecdote. I remember well when Sinornithosaurus and Microraptor were first found. Me, and many others at the time, were eagerly using these as ammo against the Jurassic Park crowd as PROOF of what Velociraptor looked like. It should also be strongly noted that this is the same time the BROAD definition of Dromaeosauridae came into vogue. Prior to 1998 or 1999 when Sinornithosaurus was discovered, the original and most often used definition of Dromaeosauridae was (Velociraptor + Dromaeosaurus). After that it became (Dromaeosaurus > Aves). Why did so many people latch onto this broader definition? I can only speak for myself but for me, it was much more effective to argue against the "yeah but as far as we know Velociraptor still has scales" crowd if you could say we had feathered examples in the same "family", just like the cat "family" (I used that exact example many times in my younger days).

But like you say, this is a massively diverse group that the latest excellent game-changing paper by Alex Dececchi et al. strongly suggests independently evolved powered flight at least once (maybe twice if Rahonavis is an unelgagiid). Now that we have ample evidence that all pennaraptorans were feathered (duh, it's right in the name now! ;) ), I think the broad definition of Dromaeosauridae has become actively unhelpful and we should go back to using Velociraptor + Dromaeosaurus. Dromaesaurus > birds already had a much better name the whole time that somehow got hijacked to include troodontids (Deinonychosauria). So we can talk about general feather trends in microraptorians, unenlagiids, dromaeosaurids, and basal deinonychosaurians like Zhenyuanlong, without making any sweeping generalizations about the whole group.

I have never considered the implications you raise in your last two paragraph about the broad definition of dromaeosauridae becoming problematic. At first, as you said, it was good for establishing feathers on all these animals. Now that the feather dispute is settled problems arise because people want to paint these animals with too uniform a brush, establish memes etc etc.

Yes reread All Yesterdays folks and based on the chatter on Witton's new book he embellishes on those themes.

I recently got into a conversation about the types of feathers in various basal groups of Tyrannoraptorans. Eventually we got onto the topic of what feather type was likely in Tyrannosaurs. I have seen a few illustrations of basal Tyrannosaurs with pennacious feathers on the arms, but is this possible of even likely? Sorry for being off topic, but this actually has a lot to do with Dromaeosaur integument. Aferall, like you have said, in 100+ million years of evolution, it's incredibly unlikely for one kind of feather pattern to be dominant. Ratite plumage, eagle/hawk plumage, quills, etc. would all be possibilities, but what if it were also true for various other groups of Theropods? Maybe even more basal groups than Dromaeousaurs at one point had pennacious feathers (or something more basal than it) but due to millions of years of evolution and selective pressures (the same pressures for Dromaeosaurs and ratites), they lost most if not all of their true pennacious feather or at least these pennacious feathers evolved into more ratite like plumage. What are your thoughts on this?

A recent paper suggest that the origin of pennaceous feathers should be decoupled from flight so... maybe? I don't think that ornithomimids are secondarily flightless. https://peerj.com/articles/2159/

A favorable hypothesis is that such "arm-wings" are useful in balance and tight turns. The stubby arms of t-rex not so great in those regards - not really obvious display mechanism as well ( the short arms in tyrants that is). A lot of options are on the table.

Hi Duane i don't know if you read this blog post of mark witton from May 16 but it covers everything thing we (publicly know, there is stuff that is awaiting proper diagnosis etc) know about azhdrachids. While hatzegopteryx is most defiantly something to be on the look out for in future papers, there is another huge and VERY robust azhie (beak tip) that has been found in javelina Texas in the same turf as quetzalcoatlus..... Another thing that he mentions is that knowledge on azhdrachids is rapidly increasing every day and that there is a great variety in body shapes and robustness etc, other wards we probably don't have a true standard to measure all azhdrachids too nor is there a general body shape to clump them I yet.

As for the whole azhdrachids pushing theropods out of niches, well I assume they mean them out competing dwarfs on the European acrhipelago new Zealand style. Other words I haven't heard any other ideas on that, course I'm not a scientist so.....

Well Tyrannosaurus and other more derived members have tiny arms, but basal Tyrannosauroids had "ordinary" arms. Proceratosaurids are among the most basal forms, yet still have long grasping arms:Guanlonghttp://static1.squarespace.com/static/51bf1cd3e4b0a897bf54112b/t/540bf67be4b08734f6c2dd41/1410070148777/Stokesosaurushttp://static.squarespace.com/static/51bf1cd3e4b0a897bf54112b/51bf3928e4b09edc5f83d0af/51bf5cd2e4b020693fe3c58a/1382740951737/Stokesosaurus.jpgBut having long arms isn't great evidence in favour of having pennacious feathers afterall. I personally find it unlikely but I was just curious. Thanks for the help.

@khalil you are right in saying tyrannosaurs don't have pennaceous feathers. Tyrannosaurus and its kin lie outside the family of coleurosaurs that have pennaceous feathers: Pennaraptora.http://cladocircles.tumblr.com/image/129825732805

D-man: Don't let the name fool you. Pennaraptora is defined as Oviraptorosaurs + Dromaeosaurs. It was named Pennaraptora because both of those groups are known to have pennaceous feathers, but that doesn't mean more basal groups can't. Yixianosaurus, for example, has them but likely lies outside Pennaraptora. Same for ornithomimids, which have attachment scars for large quilled feathers though no direct evidence yet. No feathers from the ulna or manus have been preserved with any Tyrannosauroids, so we don't know if they were pennaceous or not. Bracketing is unhelpful in this example because while compsognathids lack pennaceous feathers, so do therizinosaurs and in fact several lineages of birds like kiwi and Moa, so we know they can be lost.

I have another question about snouts and feather covering. Seeing as how the lean, naked snouted Dromie is an unjustified meme (though still completely possible, albeit overdone), would the same thing apply to various other Theropods? Tyrannosaurus for instance in cold weather areas are still portrayed (on average) with a bare snout devoid of anything. But would a full feathery snout be likely? And what of temperate to tropical weather genera? Would a fully feathered snout be unlikely?

Many possibilities... and so many intervening factors I try not to think too dogmatically about either extreme (fully feathered to mostly or entirely featherless) Was SIGIL a thing and did some theropods utilize it? what of blood flow? countercurrent heat exchange? Keep in mind that aquatic birds have their naked legs just dangling in ice cold frigid waters and do so because of countercurrent heat exchange.

Again many possibilities are on the table and I try not to think too dogmatically about situations wwe do not have direct evidence for.

Great point Duane. Well if you see a feather snouted Yutyrannus or Nanuqsaurus in my personal project don't be suprised. By the way, I think you'll absolutely LOVE my project's Dakotaraptor. I'll leave it as a suprise for now but I'll send you the picture once it's done.

One of the main things I think that needs to be considered when predicting or recreating any sort of visual display on an animal is whether the animal is or isn't built for moving engagements.

While there are carnivores/omnivores that have rather ridiculous displays, very few (if any) that I can find are built for ambush or pursuit hunting of large prey.

Turkeys, Condors, Hornbills, Storks, Cassowaries, Toucans, and many other birds all have bright displays, but none of these animals are built to pursue prey at high speed over any sort of distance. Several of them have meat in their diet, but none of them actively hunt animals that are potentially deadly to them barring maybe some crazy and rare circumstances.

It's no different across for other tetrapods.

Pretty much any carnivore that hunts something close to or exceeding its own size (Tigers, Lions, Bears, Monitor Lizards, Sharks, Raptors, Canids, Anacondas, Mustelids etc) is going to have reasonably subdued coloration in order to camoflage themselves at least reasonably well and save as much energy as possible in a hunt.

Vultures can get away with having very bright displays because of that. Bright colors are bad when trying to close distance on something, but become a tool when trying to get something else to go away.

Which, is a really long winded way of saying that I think the faster dromaeosaurs (dakotaraptor) and the ones known or suspected to hunt large prey (deinonychus) are much less likely to have had bright displays than the stockier ones. Caruncles themselves don't have to be any particular color so it doesn't remove the possibility of them being there, but it does potentially give us at least a hint to the limits of their coloration.

Also, especially when talking about the neck of a tarbosaurus, I would be VERY surprised if it were something anyone would describe as colorful even if it is ungodly awkard looking.

Very insightful comment Mr. Strong and this is an issue I have thought about a lot myself actually.

I do want to get into more deeply in future posts but my short hand argument is as such. R - strategist dominated Mesozoic ecosystems differed in fundamental ways from K- strategist dominated Cenozoic ecosystems. Large theropods basically concentrated on "browsing" on swarms of easily caught and run down juveniles and the sporadic glut of meat that the carcass of an adult dinosaur would provide. This scenario is most vivid in sauropod dominated ecosystems. IN such ecosystems there is not a high priority in stealth as meat is got from easily overwhelmed ran down youngins or occasional giant carcasses. But I would suggest that this type of ecosystem would encourage is dramatic threat displays and socio-sexual signalling devices to establish dominance over carcasses and thwart kleptoparasitic pirating of young carcasses that have been caught.

In Cenozoic communities much of the standing meat crop is concentrated in robust adults that are often times fast and predatory wary. A high emphasis on stealth is placed on these carnivores and lack of display structues commences...

There is always exceptions and shades of grey but these are my reasons ecologically why Mesozoic carnivores might be a tad more flamboyant than Cenozoic ones...